Anterograde amnesia associated with infarction of the anterior fornix and genu of the corpus callosum.

Anterograde amnesia due to infarction of the anterior fornix is a rare but unique neuropsychological syndrome. Only 2 cases have been reported previously. Lacking focal neurologic deficits, this syndrome is not easy to diagnose. Moreover, it is not fully recognized by the clinicians, making its diagnosis all the more difficult. Here we report a patient of infarction of the anterior fornix and genu of the corpus callosum who developed sudden apathy and anterograde amnesia. Unfortunately, the patient was initially diagnosed and treated as an acute psychiatric disorder by a psychiatrist, and treatment for acute cerebral infarction could not be performed. This case emphasizes the importance of suspecting this syndrome and performing brain magnetic resonance imaging immediately in the patients presenting with anterograde amnesia of sudden onset.